Improvement in circular saws



2 Sheets-Sheet. 1.

J. A. MILLER.

Circular-Saw.

- Patented Mar. 4, 1879.

2 Sheets-Sheet 2. J. A. MILLER, Circular-Saw.

No. 212.813. Patentedlvlar. 4,1879.

Irzuazzlwr N.PETERS, PHOTO-LITHOGRAPHER. WASHINGTON, D'C.

UNITED STATES PATENT OEEIOE.

JOEN A. MILLER, OE OsHEOsH, WIsOONsIN, AssIeNoR To WARREN r..

MILLER, OE BROOKLYN, NEW YORK.

IMPROVEMENT iN CIRCULAR SAWS.

Specification forming `part of Letters Patent No. 212,813, dated March 4, 1879 application tiled December 26, 1877.1

To all whom it may concern:

Be it known that I, JOHN A. MILLER, of the city of Oshkosh, county of Winnebago, and State of Visconsin, have invented certain Improvementsin Circular Saws, of which the following is a specication:

r1`he nature of my invention relates to the use of perforations through the saw, for the purpose of securing a circulation of air through the disk ot' the saw to prevent its becoming hot; also, to the form ot' the perforations or slots, which reduces their liability to become clogged with sawdust, Sac.

When slots are employed the rear edge only need be sharpened or beveled, though there is no objection to beveling the front edge, and may be an advantage in doing so in a direction parallel with the bevel of the rear side.

1t is not absolutely essential, but is prefera ble, that t-he sharpened edges of the slots should alternatethat is, each alternate slot should present its sharp edge from opposite sides of the saw.

The pertbrations should extend from near the center about two-thirds or more ot' the distance to the circumference of the saw.

The perforations may extend in curved lines or be irregularly placed. It is desirable to have them beveled from Opposite sides of the saw alternately, so that the air will be drawn through alternate perforations in opposite directions, thus creating a circulation by which the saw will be kept cool and expansion avoided.

It will be Observed that the beveled edges ot' the perforations prevent clogging.

Figure l is an elevation of the saw, showing perforations. Fig. 2 is a section of the same. Fig. 3 is a section, showing the perfo- Fig. 4 is au Fig. 5

rations direct through the saw. elevation, showing the beveled slots. is asectlon ot' the same.

To illustrate the different methods ot carrying out my invention, I have shown in the drawings one-half of the saw devoted to each method.

In Fig. 1, to the right of the dotted vertical line, the perforations are arranged, as shown, from a b, a e, 85o., and on the left in curved lines a, c, ct d, &c., the perforations being beveled from opposite sides alternately, as seen at 1 2 3 4 5 6, Sto.; but it is to be understood that I claim perforations generally, whether beveled or direct, as shown in Fi 3.

The size and number ot' the pertbrations are varied and determined by the size of tlhe saw.

In Fig. 4, to the right of the vertical dotted line, the beveled slots extend in radial lines, and on the left in curved lines.

Fig. 5 shows the beveled edges of the slots in section, as 7, S, and 9, or theymay be made as seen in the same figure at 10.

It is understood that I do not claim herein a saw such as is described and claimcdin Letters Patent of the United States granted to E. IV. Tilton and J. IV. Branch, May 22, 187 7, No. 191,198; but

What I do claim as my invention isl. A circular saw provided with perforations between near the center or eyc'of the saw and its circumference, distributed in curved lines or irregularly, substantially as shown and described.

2. A circular saw pierced with beveled or sharpened perforations between the eye and periphery, substantially as shown and described.

3. A circular saw having sharp or beveled edge slots, substantially as shown and described, for the purpose specified.

JOHN A. MILLER.

Witnesses: 4

E. PALMER,

R. 1. EIGEONE. 

